Howard, I have to ask, why is it that carriers use B-ICI and not PNNI? Is PNNI deficient in some way? ""Howard C. Berkowitz"" wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > >I would like to hear some opinions on MPLS. I have been reading about it, > >and, pardon me if I'm wrong, but it seems to me like just a reinvention of > >ATM PNNI. > > Not really. A more accurate analogy would be to say that MPLS is ATM > without cells. > > MPLS has two parts, a forwarding plane and a control plane. PNNI is > purely a control plane function. It's based on OSPF, plus a > reservation mechanism. > > MPLS control, however, doesn't have the topology discovery that PNNI > does, just the path setup using CR-LDP, LDP, or RSVP-TE. The > existence of potential paths to set up typically comes from IP > routing. I like to think of MPLS as an overdrive for IP routing, but > definitely not, as some people misconstrue it, a replacement for IP > routing. > > There is active work on Generalized MPLS (GMPLS) that extends the > forwarding based on frame/packet headers to forwarding based on TDM > time slots, wavelengths/lambdas, or physical ports. Obviously, these > are more applications for cross-connects of facilities, without the > flexibility of per-frame or per-packet decisionmaking. > > > > >I would be very interested in hearing some comments on the future of MPLS. > >Particularly since ATM PNNI seemed to have gotten nowhere with the telcos > >(and I still don't completely understand why not), then why is MPLS going to > >do any better (or is it)? > > Remember PNNI is "private network to network interface". There are > other ATM routing schemes meant for carrier use, such as B-ICI. > > > > >I would be particularly interested in hearing Howard Berkowitz's opinion on > >the future of MPLS. > > Especially considering GMPLS and emerging optical technologies, it is > a major direction. It complements, but does not replace, IP routing. > FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html > Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=5674&t=5674 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
